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Oral squamous cell carcinoma (OSCC) is a widespread malignancy with high mortality. In particular, a delay in its diagnosis dramatically decreases the survival rate. The aim of this systematic review was to investigate and summarize clinical results in the literature, regarding the potential use of salivary microRNAs (miRNAs) as diagnostic and prognostic biomarkers for OSCC patients. Twelve papers were selected, including both case–control and cohort studies, and all of them detected significantly dysregulated miRNAs in OSCC patients compared to healthy controls. Based on our results, salivary miRNAs might provide a non-invasive and cost-effective method in the diagnosis of OSCC, and also to monitor more easily its evolution and therapeutic response and therefore aid in the establishment of specific therapeutic strategies.

The present post-trial follow-up investigated the influence of titanium implants with different surface treatments on clinical behavior of soft and hard peri-implant tissues. Each of the 18 included patients received at least two adjacent implants: one control implant with a dual acid-etched (DAE) surface in their apical portion and a machined coronal part, and one test implant with a DAE surface up to its coronal portion. Peri-implant bone level change (BLC), probing depth (PD), bleeding on probing (BOP) and plaque index (PI) were recorded. A total of 42 implants was inserted. The mean follow-up period was 9.3 years (range: 5–16 years) and there were six dropouts. No implant failed. Moderate crestal bone remodeling occurred during the first year after implant insertion, with lower bone loss next to test implants compared to control ones (0.80 vs. 1.39 mm, p = 0.002). This difference was also detected at the 5- (p = 0.011), 6- (p = 0.008) and 7-year follow-up appointment (p = 0.027). No statistically significant differences were found in bone resorption between implants rehabilitated with ceramic vs. composite resin veneering material. No statistically significant differences were detected between test and control implants for BOP, PI, and PD at any time point. The results of the present study suggest that DAE surfaces reduce peri-implant bone loss in the initial phase of healing compared to machined surfaces, while they do not significantly affect soft peri-implant tissue and bone maintenance in the long-term. In conclusion, the minimally rough surfaces favour peri-implant bone maintenance and their effect is greater in the first year post implant insertion.

Background Although full‐arch immediately loaded rehabilitations are widely used nowadays, little information is available on which implant/abutment connection is the most suitable in this type of treatment. Purpose The aim of the present multicentric split‐mouth clinical trial was to compare the clinical outcomes of two different implant‐abutment connections applied in full‐arch immediate loading rehabilitations: external hexagon connection (EHC) versus internal hexagon connection (IHC). Materials and methods Twenty patients were rehabilitated with immediately loaded fixed full‐arch rehabilitations. All the implants presented the same macro‐ and micro‐topography but different implant/abutment connection. IHC were used in one randomly selected side of the jaw and EHC in the other side. Outcome measures were implant survival rate, peri‐implant marginal bone loss (MBL), plaque index (PI), probing depth (PD), and bleeding on probing (BoP) evaluated at 3, 6, 12, and 36‐month post‐loading. Any technical and biological complication was recorded. Kaplan–Meier procedure and linear mixed model were used to perform statistical analysis. Results Forty‐three EHC and 40 IHC implants were inserted. No patients dropped out and two implants failed in the first 6 months. The CSR was 97.7% for EHC and 97.5% for IHC implants. No statistically significant differences were found among the two groups for any of the parameters at any time point. At the 36‐month follow‐up visit a slight difference was found in MBL with a mean value of 1.7 mm in the EHC and of 1.9 mm in the IHC group (p = 0.355). No biologic complications were identified. Seven loosed abutment screws were identified in the entire follow‐up period, two in the EHC, and five in the IHC group without a statistically significant difference (p = 0.394). Conclusions After 36 months in function, both internal and external hexagon connections provided good clinical outcomes and were not associated with any significant difference.

The purpose of this systematic review was to investigate the clinical outcomes of frameworks made of different materials in patients with implant-supported full-arch prostheses. A literature search was conducted on MEDLINE, Scopus and Cochrane Library, until the 1st of March 2021, with the following search terms: framework or substructure combined with “dental implants”. The outcomes evaluated were: implant and prosthesis survival, bone resorption, biological and technical complications. The Cochrane Handbook for Systematic Reviews of Interventions was employed to assess the risk of bias in randomized clinical trials. The Newcastle–Ottawa quality assessment scale was used for non-randomized studies. In total, 924 records were evaluated for title and abstract, and 11 studies were included in the review: 4 clinical randomized trials and 7 cohort studies. The framework materials investigated were: gold alloy, titanium, silver-palladium alloy, zirconia and polymers including acrylic resin and carbon-fiber-reinforced composites. High implant and prosthetic cumulative survival rates were recorded by all included studies. Various materials and different fabrication techniques are now available as alternatives to traditional cast metal frameworks, for full-arch implant-supported rehabilitations. Further long-term studies are needed to validate the use of these materials and clarify their specific clinical indications and manufacturing protocols to optimize their clinical outcomes.

Background: The etiology of peri-implantitis is multifactorial, and it is not directly linked to the quantitative amount of plaque. The aim of this study was to evaluate the influence of subgingival microbiota around implants supporting full-arch restorations on clinical indexes of peri-implant health. Method: 47 patients (54 full-arch fixed rehabilitations) were included. Based on the highest value of probing depth (PD), 47 implants (in the test arch), 40 natural teeth and 7 implants (in the antagonist arch) were selected for microbiological sampling (traditional PCR and real-time PCR). Periodontal indexes (plaque index, PlI, probing depth, PD, bleeding on probing, BOP, peri-implant suppuration, PS) and marginal bone loss were also recorded. Results: Despite abundant plaque accumulation, the peri-implant parameters were within normal limits. No statistical difference was found in the microbial population around the test implants and antagonist natural teeth. Treponema denticola was present in a significantly higher amount around implants with increased PlI. Implants with increased BOP showed a significant increase in Treponema denticola and Tannerella forsythia. A significantly higher presence of Porphyromonas gingivalis, Treponema denticola and Tannerella forsythia was identified around the implants affected by peri-implantitis and in smokers. Conclusions: Peri-implantitis is characterized by a complex and polymicrobial disease, that might be influenced by the qualitative profile of plaque. Smoking might also favor implant biological complications in full-arch fixed prosthesis.

The aim of this study was to assess oral health–related quality of life (OHRQoL) of patients before, during, and after completion of implant-supported full-arch immediate loading rehabilitation according to the Columbus Bridge Protocol. Twenty-five patients with compromised dentition were rehabilitated according to the Columbus Bridge Protocol and were assessed for OHRQoL using 4 questionnaires specifically designed for this study and inspired by the Oral Health Impact Profile questionnaire. Patients assessed themselves before surgery, during the healing period (1 week and 2 months after surgery), and after definitive prosthodontic treatment (4 months after surgery). The questionnaires specifically investigated patients' pain, comfort, home oral hygiene habits, satisfaction related to esthetics, masticatory ability, phonetics and general satisfaction with the treatment. Patients reported an improvement of OHRQoL after full-arch immediate-loading rehabilitation. A statistically significant improvement in esthetics and chewing ability was found. After 4 months 92% of the patients did not feel tense about their smile, 96% did not indicate problems relating to other people or smiling, and 92% did not have difficulty eating some foods. Phonetics were a critical issue, especially in the intermediate phase of healing. One week after surgery, the percentage of patients who were very satisfied with phonetics slightly decreased from 48% to 36%. The assessment of patients' OHRQoL related to full-arch immediate-loading implant therapy exhibited a significant improvement in quality of life. The questionnaires herein presented could be an effective tool to evaluate patients' reaction to oral rehabilitation.

PURPOSE To evaluate plaque accumulation, peri-implant soft tissue inflammation, and bone resorption in patients with immediately loaded implants supporting fixed full-arch prostheses. MATERIALS AND METHODS A convenience sample of 72 patients treated with fixed full-arch prostheses supported by four to six immediately loaded implants was selected. Bleeding on probing (BOP), Plaque Index (PI), and peri-implant bone loss were measured. The Sixth European Workshop on Periodontology definitions of mucositis and peri-implantitis were used, and collected data were analyzed using a nonparametric test (Spearman's rank correlation). Correlation coefficients (ρ) were defined as follows: < 0.2 = very weak; 0.2 to 0.39 = weak; 0.4 to 0.59 = moderate; 0.6 to 0.79 = strong; 0.8 to 1.0 = very strong. RESULTS A total of 331 implants were analyzed. The mean follow-up observation time was 5.8 years (range: 1 to 14 years); mean PI and BOP were 61.7% and 21.1%, respectively; and mean bone loss was 0.89 mm (standard deviation [SD] 1.09). The mean probing depth was 1.8 mm (range: 0.5 to 5 mm). Five patients presented with one implant each affected by peri-implantitis (6.9%), and 15 patients presented with at least one implant affected by mucositis (20.8%). No correlation was found between PI and bone resorption (P = .08). Very weak correlations were found between BOP and bone resorption (ρ = 0.18; P = .001) and between PI and BOP (ρ = 0.13, P = .019). CONCLUSION The results suggest that plaque accumulation is correlated with peri-implant mucositis; however, plaque accumulation alone does not appear to be associated with bone resorption.

PURPOSE To assess bond strength and failure patterns of carbon fiber-reinforced composite (CFRC) and veneering materials. MATERIALS AND METHODS A total of 20 samples were prepared: 10 veneered with polymethylmethacrylate (group A) and 10 with composite resin (group B). Shear bond strength (SBS) was measured, and failed samples were microscopically observed. RESULTS The mean ± standard deviation (SD) SBS of specimens in group A was slightly higher (7.39 ± 0.24 MPa) than specimens in group B (5.68 ± 0.29 MPa). Microscopic observation showed an adhesive fracture pattern at the CFRC-adhesive interface in both groups. CONCLUSION Adhesion between CFRC and veneering material is reliable and predictable, although a specific protocol needs to be developed to improve adhesion.

Objectives The aim of the present study was to investigate the biocompatibility and mechanical characteristics of dental implant frameworks made of carbon fiber composite. Methods The biocompatibility of intact samples and fragments was evaluated by cell count and MTT test according to EN-ISO 10993-5:2009 directions. Destructive and non-destructive mechanical tests were performed in order to evaluate: porosity, static and dynamic elastic modulus of carbon fiber samples. These tests were conducted on different batches of samples manufactured by different dental technicians. The samples were evaluated by optical microscope and by SEM. A compression test was performed to compare complete implant-supported fixed dentures, provided with a metal or carbon fiber framework. Results Carbon fiber intact and fragmented samples showed optimal biocompatibility. Manufacture technique strongly influenced the mechanical characteristics of fiber-reinforced composite materials. The implant-supported full-arch fixed denture provided with a carbon fiber framework, showed a yield strength comparable to the implant-supported full-arch fixed denture, provided with a metal framework. Significance Carbon fiber-reinforced composites demonstrated optimal biocompatibility and mechanical characteristics. They appear suitable for the fabrication of frameworks for implant-supported full-arch dentures. Great attention must be paid to manufacture technique as it strongly affects the material mechanical characteristics.

OBJECTIVE The aim of this study was to evaluate the accuracy of 7 different implant impression techniques for full-arch prostheses. MATERIALS AND METHODS A master cast simulating an edentulous arch with 4 implants was used. Seven impression techniques were tested: open tray with polyether Impregum (OTI); open tray with splint-polyether Impregum (OTSI); closed tray with polyether Impregum; open tray with polyether Ramitec; open tray with splint-polyether Ramitec; closed tray with polyether Ramitec (CTR); open tray with impression plaster (OTP). Five impressions of the master cast were taken for each technique using an impression simulator device. Casts were realized based on those impressions (n = 35). Median values of deviation from the master cast were recorded for each cast through a 3-dimensional laser scanner. RESULTS Only OTI (P = 0.028) and OTSI (P < 0.001) presented a statistically significant difference compared to the master cast. OTP (P = 0.99) and CTR (P = 0.10) showed median values of deviation close to zero (-0.001 and -0.003 mm, respectively). CONCLUSION Stiff impression materials (such as plaster or rigid polyether) guarantee greater accuracy in cases of multiple implant impressions of patients with full-arch rehabilitations. Splinting of impression copings with acrylic resin did not improve accuracy.

Objectives Short-term results indicated that the Branemark Novum® protocol (Nobel Biocare AB, Goteborg, Sweden) allowed successful rehabilitation of mandibular edentulism with immediately loaded implants. Yet, long-term studies are lacking. The aim of the present retrospective study was to report the 11-year outcomes for patients treated according to this protocol. Material and methods Four patients treated according to the Branemark Novum protocol (Nobel Biocare AB) were followed-up to evaluate implant and prosthesis cumulative survival rate (CSR), implant stability (RFA), marginal bone loss by periapical radiographs, probing depth (PD), and possible complications. Clinical and radiographic parameters were evaluated immediately after completion of the treatment and 1, 5, and 11 years after loading. Results The 11-year implant and prosthesis CSRs were 100%. Implant stability (RFA values) remained stable over the 11-year follow-up. Small bone resorption was found next to distal implants (median 1 mm) after 11 years, while central implants showed greater bone resorption (median 4.5 mm). The PD (mean 3.75 mm at 11 years) grew together with marginal bone loss. One implant complication was detected on a central implant (crater-form bone destruction), and 10 prosthetic complications (fractures of resin or teeth), 80% of which registered on the same parafunctional patient. Conclusions The 11-year results demonstrated that the Branemark Novum protocol (Nobel Biocare AB) is a predictable technique with favorable long-term outcomes. This was a rigid protocol, which could be applied only in patients with specific anatomical characteristics of the lower jaw, but it had the merit of indicating the key factors for full-arch immediate loading rehabilitations.

Purpose: This in vitro study evaluated the adhesive strength of a technique to lute implant cylinders to metal frameworks in implant-supported prostheses and ensure a good passive fit. Materials and Methods: Different height samples were tested: In group 1, implant cylinders were 5 mm long; in group 2, they were 10 mm long. A universal testing machine (Instron) was used to perform pullout tests. Results: The luting technique provided enough adhesive strength for clinical use with greater adhesive strength in group 2 (mean pull-out strength: 2.85 kN in group 1 versus 3.79 kN in group 2). Conclusions: The luting technique provides enough adhesive strength for clinical use. Moreover, specimens with a larger surface for adhesion demonstrated higher adhesive strength compared with shorter specimens.

Purpose: The aim of this study was to analyze through a three-dimensional finite element analysis (3D-FEA) stress distribution on four implants supporting a fullarch implant-supported fixed prosthesis (FFP) using different prosthesis designs. Materials and Methods: A 3D edentulous maxillary model was created and four implants were virtually placed into the maxilla and splinted, simulating an FFP without framework, with a cast metal framework, and with a carbon fiber framework. An occlusal load of 150 N was applied, stresses were transmitted into peri-implant bone, and prosthodontic components were recorded. Results: 3D-FEA revealed higher stresses on the implants (up to +55.16%), on peri-implant bone (up to +56.93%), and in the prosthesis (up to +70.71%) when the full-acrylic prosthesis was simulated. The prosthesis with a carbon fiber framework showed an intermediate behavior between that of the other two configurations. Conclusion: This study suggests that the presence of a rigid framework in full-arch fixed prostheses provides a better load distribution that decreases the maximum values of stress at the levels of implants, prosthesis, and maxillary bone.

This prospective study reports the 6-year outcomes for patients rehabilitated with an immediate loading protocol of the maxilla (Columbus Bridge Protocol). In this study, 164 implants were inserted in 37 patients and loaded within 24 to 36 hours. Four implants failed during the first 6 months. At the 6-year follow-up, a mean bone loss of 1.52 mm was found. Significantly (P < .0083) less bone loss was found next to tapered implants compared with cylindric implants and next to machined collar implants compared with full acid-etched implants (P < .0083). No significant differences in bone loss were found in tilted versus upright implants or in mesial versus distal implant sites. In addition, there were no significant differences relating to either the degree of abutment angulation or the reason for tooth loss.

PURPOSE To measure the vertical occlusal forces transmitted through crowns made of different restorative materials onto simulated peri-implant bone. MATERIALS AND METHODS The study was conducted using a masticatory robot that is able to reproduce the mandibular movements and forces exerted during mastication. During robot mastication, the forces transmitted onto the simulated peri-implant bone were recorded using nine different restorative materials for the simulated single crown: zirconia, two glass-ceramics, a gold alloy, three composite resins, and two acrylic resins. Three identical sample crowns for each material were used. Each crown was placed under 100 masticatory cycles, occluding with the flat upper surface of the robot to evaluate the vertical forces transmitted. Two-way analysis of variance was used. Alpha was set at .05. RESULTS The statistical evaluation of the force peaks recorded on the vertical z-axis showed mean values of 641.8 N for zirconia; 484.5 N and 344.5 N, respectively, for the two glass-ceramics; 344.8 N for gold alloy; 293.6 N, 236 N, and 187.4 N, respectively, for the three composite resins; and 39.3 N and 28.3 N, respectively, for the two acrylic resins. Significant differences were found between materials (P < .0001), except for the comparison between gold alloy and one of the glass-ceramics. CONCLUSION Composite and above all acrylic resin crowns were more able to absorb shock from occlusal forces than crowns made of zirconia, ceramic material, or gold alloy.

The aim of this paper is to describe a technique for sinus floor augmentation with a 1-step crestal approach where the residual bone is ≤ 7.5mm. 36 implants were installed in 25 patients in the atrophic posterior maxilla immediately after sinus floor elevation. Sinus floor elevation was performed with a crestal approach using either osteotomes and burs or piezosurgery. Standardized intraoral radiographs were taken prior to surgery and 1 year after surgery. The mean residual bone height was 5.61 mm (range 3-7.5mm). The mean gain of sinus elevation was 6.78 mm (range 3.5-10mm) at 1 year after surgery. Two patients dropped out of the study. Of the 23 patients completing the study, one implant failed, whilst the remaining 33 implants were stable 12 months after surgery (cumulative survival rate 97%). A statistically significantly higher bone height was achieved with tapered implants compared with cylindrical implants (P

The aim of the present research was to measure in vitro the chewing load forces transmitted through crowns made of different prosthetic restorative materials onto the dental implant. A masticatory robot that is able to reproduce the mandibular movements and the forces exerted during mastication was used. The forces transmitted to the simulated periimplant bone during the robot mastication were analysis of variance (ANOVA) was used. The zirconia and the ceramic crowns transmitted significantly greater forces (p-value < 0.0001) than the other crowns tested. Dental materials with lower elastic modulus were better able to ansorb shock from acclusal forces than more rigid materials.

Statement of problem Immediate occlusal loading of dental implants in the edentulous mandible has proven to be an effective, reliable, and predictable procedure. There is little long-term data available on similar treatments in the edentulous maxilla. Purpose The purpose of this study was to evaluate the 12-month implant survival after immediate loading of 4 to 6 implants with fixed screw-retained prostheses in edentulous maxillae. Material and methods Twenty-one patients, edentulous or with remaining teeth to be extracted in the maxilla, received 4 to 6 implants (n=111). The patients were restored with screw-retained fixed provisional prostheses supported by palladium-alloy frameworks within 24 hours after surgery. Insertion torques for implants were at least 40 Ncm. Implants, grouped as tapered or cylindrical screws, were placed in healed bone or extraction sockets. Implants were also classified as either vertical or off-angle. Definitive prostheses were placed after a mean healing time of 18 weeks. Radiographic examinations were made at the time of placement of provisional prostheses and 12 months later. Between-groups bone resorption was compared using 2-way ANOVA (α=.05). Results The mean follow-up time for all of the patients was 20 months (range, 13 to 28 months). The cumulative implant survival rate at the 12-month follow-up visits (after surgery) was 92.8%; the prostheses survival rate was 100%. No significant differences were found between the survival of tapered or cylindrical screw-type implants placed in postextraction sockets versus those in healed edentulous sites or between vertical and off-angle placed implants. Eight implants failed during the first 3 months, 5 of which were the most distal implants. The mean reduction in marginal bone height over the 12-month observation period was 0.84 mm (CI 95%; 0.68-0.99 mm). Conclusions In this study with 12-month follow-up, 4 to 6 implants were sufficient to successfully support fixed implant screw-retained prostheses in the edentulous maxillae of 21 patients. (J Prosthet Dent 2008;99:351-360)